Idiopathic Intracranial Hypertension with Normal Cerebrospinal Fluid Pressure

I have read with enthusiasm the article published recently,[1] based on which I would like to raise several concerns: 1. It is unclear how the diagnosis of idiopathic intracranial hypertension was made. In idiopathic intracranial hypertension, the opening pressure should be high. Based on this study, every patient with pale optic disc and normal lumbar puncture should be diagnosed as having idiopathic intracranial hypertension. The opening pressure of 18 cm H2O measured in this case report is not considered high. Additionally, the position (supine or lateral decubitus) during the lumbar puncture was not disclosed in the published article. In a large study conducted to find the reference range for cerebrospinal fluid pressure in 472 children,[2] a threshold value of 28 cm H2O in the lateral recumbent position was set for high intracranial pressure. Authors recommended that for children an opening pressure above 28 cm H2O should be considered as elevated intracranial pressure. Another study also considered cerebrospinal fluid measures ≤ 28 cm H2O as ”normal” for most children.[3] The two case reports that the authors cited with normal cerebrospinal fluid pressure had other features of idiopathic intracranial hypertension such as papilledema, headache, and pulsatile tinnitus.